Spectroscopic studies of photosystem II in chlorophyll d-containing Acaryochloris marina.
Spectroscopic studies of photosystem II in chlorophyll d-containing Acaryochloris marina.
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含叶绿素 d 的 Acaryocholis 码头光系统 II 的光谱研究。
DOI：
10.1021/bi048314c
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发表时间：
2005
期刊：
影响因子：
2.9
通讯作者：
T. Wydrzynski
中科院分区：
文献类型：
--
作者：
M. Razeghifard;Min Chen;Joseph L. Hughes;Joel Freeman;E. Krausz;T. Wydrzynski
研究了含叶绿素d的蓝藻Acaryochloris marina（A. marina）的时间分辨电子顺磁共振（EPR）光谱，在室温下，叶绿素荧光，低温光学光谱进行了研究。为了最大限度地提高在这种生物体的完整细胞中测量PSII ET的能力，生长条件进行了优化，以提供最高的比O（2）活性，并调整了EPR测量酪氨酸Z（Y（Z））减少的仪器参数，以获得最佳的信噪比。Y（Z）（*）还原动力学分析表明，ET在A. marina与高等植物和其他蓝细菌中的没有区别。同样地，在第一质体醌受体Q（A）和PSII的供体侧之间的电荷重组动力学通过叶绿素荧光衰减在秒时间尺度上监测，在A之间没有显著差异。marina和非叶绿素d生物，而低温光学吸收光谱鉴定了A. marina as pheophytin a.结果表明，如果A.海洋是由叶绿素d，而不是叶绿素a，那么必须有非常不同的相互作用与蛋白质环境，以占ET属性，这是类似于高等植物和其他蓝藻。然而，A.玛丽娜在动力学上没有改变。
Photosystem II (PSII) electron transfer (ET) in the chlorophyll d-containing cyanobacterium Acaryochloris marina (A. marina) was studied by time-resolved electron paramagnetic resonance (EPR) spectroscopy at room temperature, chlorophyll fluorescence, and low-temperature optical spectroscopy. To maximize the ability to measure PSII ET in the intact cells of this organism, growth conditions were optimized to provide the highest specific O(2) activity and the instrumental parameters for the EPR measurements of tyrosine Z (Y(Z)) reduction were adjusted to give the best signal-to-noise over spectral resolution. Analysis of the Y(Z)(*) reduction kinetics revealed that ET to the oxygen-evolving complex on the donor side of PSII in A. marina is indistinguishable from that in higher plants and other cyanobacteria. Likewise, the charge recombination kinetics between the first plastoquinone acceptor Q(A) and the donor side of PSII monitored by the chlorophyll fluorescence decay on the seconds time scale are not significantly different between A. marina and non-chlorophyll d organisms, while low-temperature optical absorption spectroscopy identified the primary electron acceptor in A. marina as pheophytin a. The results indicate that, if the PSII primary electron donor in A. marina is made up of chlorophyll d instead of chlorophyll a, then there must be very different interactions with the protein environment to account for the ET properties, which are similar to higher plants and other cyanobacteria. Nevertheless, the water oxidation mechanism in A. marina is kinetically unaltered.